sounds like Brazil changed their laws that people from the Schengen area (EU, not UK) can only stay in Brazil 90 days, then leave for 90 days, then come back.
Before you could stay 90 days, and extend another 90 days.

But, now I heard two stories, where people extended 90+90 days without any problem...

Anyone from Schnegen area who recently extended their visa without any problem???